In the process of manufacturing a thin film transistor liquid crystal display (TFT-LCD), it is inevitable to involve bonding connection between a printed circuit board (PCB) and a flexible printed circuit board (FPCB).
The bonding connection between a PCB and a FPCB generally comprises steps as follows: first, a coupling end of the PCB and a coupling end of the FPCB are aligned and fitted, bonding adhesive is applied between the fitted coupling ends of the PCB and the FPC board, and then the coupling ends of the PCB and the FPCB are pressed by a pressing device, so as to bond both coupling ends together.
The pressing device may heat a to-be-pressed area while applying pressure to the area, to cause the bonding adhesive applied between the fitted coupling ends to be melted, so that the coupling ends of the PCB and the FPCB are bonded tightly. For example, in a traditional pressing process, the pressing temperature of the pressing device usually needs to be controlled in the range of 160-180 degrees centidegrade, which can ensure the best bonding performance of the bonding adhesive. In addition, when the coupling ends of a PCB and a FPCB having different circuits are pressed, the pressing temperature required for the pressing device is different. Thus, the pressing temperature of the pressing device during an actual pressing process needs to be controlled accurately.
To control the pressing temperature of the pressing device during the pressing process accurately, generally, a temperature measuring sample similar to the actual to-be-pressed product (i.e. the structure formed by fitting the PCB and the FPCB together) needs to be manufactured, and a strip-like thermometer is provided in the temperature measuring sample. When the temperature measuring sample is pressed, the pressing temperature of the pressing device can be measured by the strip thermometer in the temperature measuring sample, so that during the actual pressing process, the pressing temperature of the pressing device can be controlled within the optimum temperature range according to actually requirement.
The temperature measuring sample is generally manufactured by setting the best temperature measuring point of the strip thermometer to be at the center (i.e. the intersection of the diagonals of a goldfinger) of the coupling end (e.g. the goldfinger) of the PCB, and then fitting the FPC thereon. The temperature measuring sample can measure the pressing temperature of the pressing device, so as to adjust and control the pressing temperature during the actual pressing process.
Currently, the temperature measuring sample is manufactured by manually setting the best temperature measuring point of the strip thermometer to be at the center of the coupling end of the PCB through observation with human eyes. However, as a human hand is prone to shake during the manual setting, which can easily cause the best temperature measuring point to deviate from the center of the coupling end. For example, as shown in FIG. 1, the best temperature measuring point 21 of a strip thermometer 2 is prone to deviate from a center point of a coupling end 31 in a width direction due to manual alignment, since the width of the coupling end 31 is quite small, the best temperature measuring point 21 easily deviates into an interval region 32 between adjacent coupling ends 31, and the interval region 32 is slightly recessed with respect to the coupling end 31. Therefore, the finally-measured temperature may be lower than the actual temperature at the width center of the coupling end 31, and along the width direction of the coupling end 31, every deviation of 0.1 mm from the width center of the coupling end 31 may cause the measurement result to be lowered by 2-3 degrees centigrade. As shown in FIG. 2, the best temperature measuring point 21 of the strip thermometer 2 deviates from a center point of the coupling end 31 in a length direction, resulting in that the best temperature measuring point 21 will not coincide with center of a pressing end of a pressing device. Therefore, the finally-measured temperature may be lower than the actual temperature of the pressing end of the pressing device, and along the length direction of the coupling end 31, every deviation of 0.5 mm from the length center of the coupling end 31 may cause the measurement result to have a deviation of 3-5 degrees centigrade.